Wireless communications devices such as the BlackBerry® by Research In Motion Limited provide a variety of useful functions, such as voice communication, e-mail and Web browsing. Of growing popularity are mapping and navigation applications or other location-based services that take advantage of a location-fixing system such as a Global Positioning System (GPS) receiver, either embedded as a GPS chipset or externally connected to the device (e.g. via Bluetooth®).
However, the GPS receiver draws a substantial amount of current, thus diminishing the battery life of the wireless communications device. Accordingly, a technique to selectively disable the GPS chip in order to prolong battery life is highly desirable.
One such technique is proposed by Deblauwe et al. in a publication entitled “Hybrid GPS and GSM localization—energy-efficient detection of spatial triggers” published in Positioning, Navigation and Communication, 2008. WPNC 2008, 27-27 March 2008 pp. 181-189. This technique compares the wireless device's current location as determined based on GSM measurements with the last position fix obtained by the GPS chip. This technique can be used to reactivate the GPS chip if the positions differ. However, there remains a need for a technique that can be used to both reactivate the GPS chip and also to deactivate the GPS chip.
Accordingly, an improved technique to selectively disable the GPS chip in order to prolong battery life remains highly desirable.
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.